iommu/arm-smmu-v3-iommufd: Require exactly one Stream ID for a vDEVICE

arm_vsmmu_vsid_to_sid() maps a guest's vSID to a single physical Stream ID
taken from master->streams[0], assuming a device has exactly one stream. A
device with several streams gets only its first one mapped, so a guest vSID
invalidation cannot reach the others' ATC and IOTLB entries; a device with
none makes master->streams a ZERO_SIZE_PTR, read out of bounds.

Add an arm_vsmmu_vdevice_init() op to reject the vDEVICE with -EOPNOTSUPP
when master->num_streams is not one, rather than mapping it silently.

Fixes: d68beb276ba26 ("iommu/arm-smmu-v3: Support IOMMU_HWPT_INVALIDATE using a VIOMMU object")
Link: https://patch.msgid.link/r/b15f2b73520f389f3f57881da2f040e7bdc18876.1783311134.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Assisted-by: Claude:claude-opus-4-8
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

0 files changed, 0 insertions, 0 deletions